The present invention relates to dielectric compositions for electronic applications, and more particularly to a low loss, substantially lead free dielectric composition that is co-fireable with a ceramic material for forming multilayer ceramic devices.
The use of green ceramic tapes has become popular in the manufacture of multilayer ceramic devices for routing electronic circuitry. U.S. Pat. No. 5,801,108 (hereby expressly incorporated by reference herein) addresses various engineering constraints encountered in the manufacture of such devices. Desirably, such devices will exhibit attractive values of xe2x80x9cQxe2x80x9d, a dimensionless property in the radio frequency field that is inversely related to the loss factor of a given material (i.e., higher Q values correspond to lower loss).
It is becoming more popular to build such devices by using a ceramic green tape, and building layers on the tape. One way to do this is to employ a paste of a desired material, such as a desired particulated material in a suitable binder. Upon processing, the binder is eliminated and the particulates of the desired material sinter to form a more densified structure. There is a need for improved materials for making such devices, and preferably materials that are substantially free of lead, have relatively flexible processing characteristics, and exhibit an attractive dielectric constant and Q value.